In all of rock 'n' roll history, one of the most misguided if entirely memorable refrains came in an otherwise excellent 1965 song by The Who. "I hope I die before I get old," they declared in "My Generation." I doubt that many people who joyfully sang along with those lyrics 50 years ago really believed them, except perhaps metaphorically.

But the song captured something that was in the air then and has never fully left us. Every generation considers itself special, but the post-World War II period saw the rise of a particularly powerful brand of generational consciousness and it permeated American politics.

John F. Kennedy built his career on the theme. He was first elected to Congress in 1946 at age 29 on the slogan: "The New Generation Offers a Leader." Seeing no need to change what had worked for him, he accepted the Democratic presidential nomination in 1960 by declaring it was time "for a new generation of leadership -- new men to cope with new problems and new opportunities."

Since Kennedy, many other politicians have sounded the generational trumpet. Joe Biden and Gary Hart both riffed on it in the 1980s. So did Bill Clinton in the 1990s and Barack Obama seven years ago, with more success.

This week, it was Marco Rubio's turn. "This election is a generational choice about what kind of country we will be," he declared in announcing his presidential candidacy on Monday, the day after Hillary Clinton launched hers. Her entry gave him a convenient opening for the sound bite that reverberated across the media.

"Now, just yesterday," he said, "a leader from yesterday began a campaign for president by promising to take us back to yesterday. Yesterday is over." In case you missed the point, he warned of the dangers of "going back to the leaders and ideas of the past."

For Rubio, the age thing gives him a chance to go after Clinton directly, but also allows him to take a poke at his rival, Jeb Bush (b. Feb. 11, 1953), without saying a single bad word about his one-time mentor.

On the other hand, Rubio (b. May 28, 1971) can't make much of the fact that he is all of five months younger than Ted Cruz (b. Dec. 22, 1970), and it's not clear where the past/future dynamic leaves him vis-a-vis Scott Walker (b. Nov. 2, 1967) or Rand Paul (b. Jan. 7, 1963). Generational politics doesn't always work, as Biden and Hart can testify.

There is also this: People's attitudes about the ideal age for a candidate are very closely related to how old their partisan or ideological favorite is. I rather doubt that Rubio will say a nasty word about Ronald Reagan (b. Feb. 6, 1911). Reagan was elected president in 1980 at the age of 69, which happens to be the age Hillary Clinton (b. Oct. 26, 1947) will be on Election Day 2016 -- except that, as you can see, she'll be a few months younger than he was.

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And while Rubio casts himself as an innovative thinker, it's quite hard to distinguish between what he's saying and what Reagan ran on 35 years ago. In his announcement, Rubio spoke with compassion about "small-business owners who are left to struggle under the weight of more taxes, more regulation and more government." Nothing new there. He spoke of "our leaders ... taxing and borrowing and regulating like it's 1999." Change "1999" to "1979" and that could be the Gipper talking.

Rubio said we needed to "remember that the family, not the government, is the most important institution in our society." Of course that's true at one level, although the sort of government we have powerfully affects the kind of lives families can have. This, presumably, is why Rubio is running for president. But however you look at it, his idea here is several hundred, and maybe several thousand, years old.

But the biggest challenge to Ponce de Leon politics is that the younger generation doesn't always buy in. Reagan split the votes of those 18-29 years old with Jimmy Carter in 1980, and in 1984, at the age of 73, won 59 percent of the ballots cast by the under 30s.

Playing the youth-and-future card may well be Rubio's best option. But to make it work, he'll have to persuade those who heard the rest of his speech and wondered whether he is proposing to lead us forward into -- well, yesterday.